Recent years have seen an increase in the number of applications for services of, for example, video on demand type services. Examples of such services include video-conferencing through the Internet, digital video broadcasting, and streaming of video contents. These applications depend on transmission of video information. These applications require that such video data having a substantial amount of digital data is transmitted through conventional transmission channels each having a limited bandwidth or recorded on conventional recording media each having a limited data capacity. Accordingly, in order to transmit the video data using a conventional transmission channel and to record the video data onto a conventional recording medium, it is inevitable to compress or reduce the amount of the video data.
For the purpose of compressing video data, many video coding standards have been developed. For the purpose of compressing video data, many video coding standards have been developed. Such video coding standards are, for instance, International Telecommunication Union Telecommunication Standardization Sector (ITU-T) standards denoted as H.26x and ISO/IEC standards denoted as MPEG-x. The most advanced video coding standards are currently the standards denoted as H.264/AVC or MPEG-4/AVC (see Non-patent Literature 1 and Non-patent Literature 2).
In addition, in the High Efficiency Video Coding (HEVC) that is the next-generation image coding standard, various considerations for increasing coding efficiency have been made (see Non-patent Literature 3).